RE: 7mm Mag
7mm has heavy recoil, and is overkill for whitetail shots taken under 100 yards. Others have suggested for you to check into getting a 30-30. I must disagree due to the size of slug (causing significant drop and slow velocity) in a 30-30 cartridge. I would suggest a .243 or possibly a .270 for larger body deer.
-Gooch-